Stable carbon isotopes of earthworms in ten different habitats were analyzed to reveal crop rotation history in arid areas, Luoyang, Henan Province, China. The results of the present study indicated that δ13C values of earthworms ranged from -18.3‰ to -25.6‰ and show great variations. Based on the mass balance theory of stable isotopes, the distribution percentages of C3 crops incorporated into earthworms′ diets are ranged from 40.%1 to 99.4%, respectively in the ten different habitats. The above data suggest that digested diets of earthworms are dependent on different C3/C4 crop rotation model. We found a close correlation between C4 crop percentage revealed from δ13C values of earthworms and rotation frequencies by C4 corns based on the oral interview with farmers. δ13C values of earthworms basically reflected the carbon isotopes of winter wheat in habitats never undergoing rotation by corn in recent 10 years. However, δ13C values of earthworms become significantly less negative in habitats where alternative rotation by corn in recent 10 years. It seemed that δ13C of earthworms actually reflected cropping system in the research habitats.